https://invisible-island.net/xterm/xtoolkit/
XtGetKeyboardFocusWidget - extension event handling
#include <X11/Intrinsic.h>
Widget XtGetKeyboardFocusWidget(Widget widget);
widget Specifies the widget for this event handler. Must be of
class Core or any subclass thereof.
XtGetKeyboardFocusWidget function returns the widget that would be the
end result of keyboard event forwarding for a keyboard event for the
specified widget.
XtInsertEventTypeHandler(3), XtRemoveEventTypeHandler(3), XtRegisterEx-
tensionSelector(3), XtSetEventDispatcher(3), XtDispatchEventToWidget(3)
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface
X Version 11 libXt 1.3.1 XtGetKeyboardFocusWidget(3)